package com.data.geektime.week_00;

import com.data.entity.ListNode;

// 合并两个有序链表
public class Solution21 {

  public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
    ListNode dummy = new ListNode(0);
    ListNode pre = dummy;
    while (l1 != null && l2 != null) {
      if (l1.val <= l2.val) {
        pre.next = l1;
        l1 = l1.next;
      } else {
        pre.next = l2;
        l2 = l2.next;
      }
      pre = pre.next;
    }
    pre.next = l1 == null ? l2 : l1;
    return dummy.next;
  }
}
